INFO: task syz.2.1952:18425 blocked for more than 144 seconds. Not tainted 6.12.0-rc5-syzkaller-00308-g3e5e6c9900c3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1952 state:D stack:28592 pid:18425 tgid:18420 ppid:17210 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5730 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:418 [inline] do_coredump+0x82f/0x4160 fs/coredump.c:575 get_signal+0x237c/0x26d0 kernel/signal.c:2902 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a6d77e719 RSP: 002b:00007f1a6d1ff0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f1a6d936060 RCX: 00007f1a6d77e719 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f1a6d936064 RBP: 00007f1a6d936058 R08: 00007f1a6e4ad080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1a6d936064 R13: 0000000000000000 R14: 00007ffc9181a340 R15: 00007ffc9181a428 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 2 locks held by getty/5600: #0: ffff8880352720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:31/6232: #0: ffff888030857148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204 #1: ffffc9000c5cfd80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205 #2: ffffffff8fac53e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcf/0x14d0 net/ipv6/addrconf.c:4196 3 locks held by kworker/u8:50/14805: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204 #1: ffffc9000dd37d80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205 #2: ffffffff8fac53e8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:276 5 locks held by kworker/u8:51/14807: #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204 #1: ffffc9000dcf7d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205 #2: ffffffff8faaf750 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xbb/0xb40 net/core/net_namespace.c:580 #3: ffffffff8fac53e8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x8f/0x9b0 net/core/dev.c:11938 #4: ffffffff8ddc30f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 1 lock held by syz.2.1952/18421: 3 locks held by syz.5.2074/19199: #0: ffff88807f148d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:481 #1: ffff88807f148078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x34c/0x1260 net/bluetooth/hci_sync.c:5193 #2: ffffffff8fd2af08 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline] #2: ffffffff8fd2af08 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xc4/0x260 net/bluetooth/hci_conn.c:2592 1 lock held by syz.5.2264/20408: #0: ffffffff8ddc30f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 1 lock held by syz-executor/20490: #0: ffffffff8fac53e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fac53e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6672 5 locks held by syz.1.2301/20666: 1 lock held by syz-executor/20702: #0: ffffffff8fac53e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fac53e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6672 4 locks held by dhcpcd-run-hook/20789: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc5-syzkaller-00308-g3e5e6c9900c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5963 Comm: kworker/1:4 Not tainted 6.12.0-rc5-syzkaller-00308-g3e5e6c9900c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events free_obj_work RIP: 0010:unwind_next_frame+0x567/0x20c0 arch/x86/kernel/unwind_orc.c:512 Code: 0f 9e c2 84 c0 0f 95 c0 84 c2 0f 85 0e 15 00 00 4c 89 f2 44 0f b6 79 05 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 <4c> 89 f2 83 e2 07 41 c0 ef 03 41 83 e7 01 38 d0 7f 08 84 c0 0f 85 RSP: 0018:ffffc900043977b8 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff90bac400 RDX: 1ffff92000872f0b RSI: 0000000000000001 RDI: ffffffff90361b8c RBP: ffffc90004397870 R08: ffffffff90bac430 R09: ffffffff90bac404 R10: ffffc90004397828 R11: 000000000000edcb R12: ffffc90004397878 R13: ffffc90004397828 R14: ffffc9000439785d R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000f23000 CR3: 00000000245ec000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kmem_cache_free+0x152/0x4b0 mm/slub.c:4681 free_obj_work+0x341/0x630 lib/debugobjects.c:331 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244